From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-11.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 31982C432BE for ; Tue, 31 Aug 2021 16:25:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0B331610CD for ; Tue, 31 Aug 2021 16:25:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240026AbhHaQ0J (ORCPT ); Tue, 31 Aug 2021 12:26:09 -0400 Received: from foss.arm.com ([217.140.110.172]:56420 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239964AbhHaQ0G (ORCPT ); Tue, 31 Aug 2021 12:26:06 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 69AD06D; Tue, 31 Aug 2021 09:25:10 -0700 (PDT) Received: from [192.168.0.14] (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 417CF3F766; Tue, 31 Aug 2021 09:25:08 -0700 (PDT) Subject: Re: [PATCH v1 12/20] x86/recstrl: Add per-rmid arch private storage for overflow and chunks To: Jamie Iles Cc: x86@kernel.org, linux-kernel@vger.kernel.org, Fenghua Yu , Reinette Chatre , Thomas Gleixner , Ingo Molnar , Borislav Petkov , H Peter Anvin , Babu Moger , shameerali.kolothum.thodi@huawei.com, D Scott Phillips OS , lcherian@marvell.com, bobo.shaobowang@huawei.com References: <20210729223610.29373-1-james.morse@arm.com> <20210729223610.29373-13-james.morse@arm.com> From: James Morse Message-ID: <5caa74a5-a73d-a5ce-9169-396ad3727386@arm.com> Date: Tue, 31 Aug 2021 17:25:01 +0100 User-Agent: Mozilla/5.0 (X11; Linux aarch64; rv:78.0) Gecko/20100101 Thunderbird/78.10.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-GB Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Jamie, On 11/08/2021 18:14, Jamie Iles wrote: > On Thu, Jul 29, 2021 at 10:36:02PM +0000, James Morse wrote: >> resctrl_arch_rmid_read() is intended as the function that an >> architecture agnostic resctrl filesystem driver can use to >> read a value in bytes from a counter. Currently the function returns >> the mbm values in chunks directly from hardware. For bandwidth >> counters the resctrl filesystem provides the number of bytes >> ever seen. Internally mba_sc uses a second prev_bw_msr to calculate >> the bytes read since the last mba_sc invocation. >> >> MPAM's scaling of counters can be changed at runtime, reducing the >> resolution but increasing the range. When this is changed the prev_msr >> values need to be converted by the architecture code. >> >> Add storage for per-rmid private storage. The prev_msr and chunks >> values will move here to allow resctrl_arch_rmid_read() to always >> return the number of bytes read by this counter. >> diff --git a/arch/x86/kernel/cpu/resctrl/core.c b/arch/x86/kernel/cpu/resctrl/core.c >> index 8a3c13c6c19f..27c93d12ca27 100644 >> --- a/arch/x86/kernel/cpu/resctrl/core.c >> +++ b/arch/x86/kernel/cpu/resctrl/core.c >> @@ -432,6 +432,28 @@ static int domain_setup_ctrlval(struct rdt_resource *r, struct rdt_domain *d) >> +static int arch_domain_mbm_alloc(u32 num_rmid, struct rdt_hw_domain *hw_dom) >> +{ >> + size_t tsize; >> + >> + if (is_mbm_total_enabled()) { >> + tsize = sizeof(*hw_dom->arch_mbm_total); >> + hw_dom->arch_mbm_total = kcalloc(num_rmid, tsize, GFP_KERNEL); >> + if (!hw_dom->arch_mbm_total) >> + return -ENOMEM; >> + } >> + if (is_mbm_local_enabled()) { >> + tsize = sizeof(*hw_dom->arch_mbm_local); >> + hw_dom->arch_mbm_local = kcalloc(num_rmid, tsize, GFP_KERNEL); >> + if (!hw_dom->arch_mbm_local) { >> + kfree(hw_dom->arch_mbm_total); >> + return -ENOMEM; >> + } >> + } >> + >> + return 0; >> +} >> + >> @@ -481,6 +503,11 @@ static void domain_add_cpu(int cpu, struct rdt_resource *r) >> return; >> } >> >> + if (r->mon_capable && arch_domain_mbm_alloc(r->num_rmid, hw_dom)) { >> + kfree(d); > > Does this error path and subsequent ones in domain_add_cpu also need to > undo the allocations from arch_domain_mbm_alloc? This one needs to free the ctrl_val array, as does the path from resctrl_online_domain(). Yes, resctrl_online_domain() needs to free the two mbm arrays. Thanks! Its probably cleanest to add some helper in patch 3 that kfree()s anything that might have been allocated, and add-to/remote-from that over time. The root structure is kzalloc()d , so shouldn't need an elaborate and verbose unwind/goto-nest. Thanks, James